A mid 18th century Naval ship’s elm single pulley block, made in three parts – pulley, pin and shell.

Height:  38 cm.

Width:  30 cm.

Depth:  15 cm.

For a similar single pulley block see the collection of: Chatham Historic Dockyard: https://collection.thedockyard.co.uk/objects/9051/single-block

In sailing, a block is a single or multiple pulley. One or a number of sheaves are enclosed in an assembly between cheeks or chocks. In use, a block is fixed to the end of a line, to a spar, or to a surface. A line (rope) is reeved through the sheaves, and maybe through one or more matching blocks at some far end, to make up a tackle. A large sail-powered warship in the 18th and 19th century required more than 1,400 blocks of various kinds.